1. Field of the Invention
This invention relates to a process for preparing macromonomers from polymers containing silyl ether groups.
2. Background
D. Brandes and A. Blaschette, J. Organomet. Chem., 99 (2), C33-5 (1975) disclose the reaction of trimethylsilyl-t-butyl peroxide with acetyl chloride or fluoride to give the acylated peroxide CH.sub.3 C(O)OO(CH.sub.3).sub.3 and (CH.sub.3).sub.3 SiX wherein X is Cl or F. No reaction with silyl ethers or unsaturated acyl fluorides is suggested, and only low molecular weight compounds are disclosed.
P. Lutz et al., Polymer Bull., 12, 79 (1984) disclose the preparation of polyalkylmethacrylate macromonomers by the reaction of terminal carbanionic sites with electrophilic reagents such as p-vinylbenzyl or p-isopropenylbenzyl bromide, or methacroyl chloride. Methacroyl chloride was found to be non-selective, a sharp increase in molecular weight and carbanion attack on the double bond being observed.
S. L. Beaucage et al., Tetrahedron Lett., 20, 1691 (1977) disclose the acylation of trialkylsilyl ethers with various acyl anhydrides (R'CO).sub.2 O, wherein R' may be CH.sub.3 --, (CH.sub.3).sub.3 C--, C.sub.6 H.sub.5 -- or CH.sub.3 (CH.sub.2).sub.12 --, in the presence of excess fluoride ion. No unsaturated moieties are included in R'. The use of acid chlorides leads to undesirable side reactions.
R. A. Olofson and J. Cuomo, Tetrahedron Lett., 21, 819 (1980) disclose fluoride ion catalyzed O-acylation of silyl enol ethers with compounds of the type RXC(O)F wherein X is O, NR' or a single bond, R is a cyclic or acyclic aliphatic radical and R' is methyl or, together with R, morpholino. R includes one unsaturated group, CH.sub.2 .dbd.C(CH.sub.3)-- when X is O. There is no disclosure of acylation with unsaturated acyl fluorides.
R. Asami et al., Polymer Preprints (ACS), 27 (1), 186 (1986) disclose macromonomers of poly(methyl methacrylate) prepared by Group Transfer Polymerization (GTP) wherein the "living" ends (silyl ketene acetals) are capped with 4-bromomethylstyrene, or wherein the polymerization is initiated with a styryl-functional silyl ketene acetal. Acyl fluorides or silyl ethers are not disclosed.
Macromonomers prepared by polymerizing methyl methacrylate by GTP using a styryl terminated silyl ketene acetal initiator, with the resulting styryl-terminated polymer being reacted with methanol to form the macromonomer, are disclosed in Japanese publication J6 2062-801-A
B. C. Anderson et al., Macromol., 4, 1599 (1981) disclose the preparation of macromonomers from anionically polymerized poly(methyl methacrylate) (PMMA) by capping anionic ends with allyl bromide or 4-bromo- or 4-iodomethylstyrene.
Terminally unsaturated acyl fluorides are known or are obvious compounds. The preparation and use of vinyl sulfonyl fluoride or 1-methylvinyl sulfonyl fluoride is disclosed by J. J. Krutak et al., J. Org. Chem., 44, 3847 (1979); U.S. Pat. No. 4,269,790; DE No. 2,557,523; and S. A. Rostovtsev et al., Vysokomol. Soedin., Ser. A, 9, 289 (1967).
The preparation of terminally unsaturated (meth)acrylic polymers or oligomers (macromonomers) by the reaction of silyl ether groups in (meth)acrylic polymers or oligomers with terminally unsaturated acyl fluorides or sulfonyl fluorides has not been disclosed in the art. Selectivity in a Michael-type addition to .alpha.,.beta.-unsaturated acyl/sulfonyl fluorides is also not disclosed in the art.
Silyl ether-functional (meth)acrylic polymers are known. Silyl ether-terminated (meth)acrylic polymers are most conveniently prepared by procedures described in U.S. Pat. Nos. 4,414,372; 4,417,034; 4,508,880; 4,524,196; 4,581,428; 4,588,795; 4,598,161; 4,605,716; 4,622,372; 4,656,233; 4,659,782; 4,659,783; and 4,681,918; and in commonly assigned U.S. patent application Ser. Nos. 660,588 filed Oct. 18, 1984 now U.S. Pat. No. 4,711,942; 912,117 and 912,118 filed Sept. 29, 1986 now U.S. Pat. No. 4,732,955; 934,826 filed Nov. 25, 1986, now U.S. Pat. No. 4,783,500; 004,831 filed Jan. 13, 1987; 007,758 filed Jan. 27, 1987, now U.S. Pat. No. 806,605; and 048,958 filed May 19, 1987. These techniques, in summary, comprise polymerizing an acrylic or maleimide monomer to a "living" polymer in the presence of:
(i) a tetracoordinate organo (Si, Sn or Ge) initiator compound having at least one initiating site including such a compound having at least one oxygen, nitrogen or sulfur atom attached to the Si, Sn or Ge; and
(iii) a co-catalyst which is a source of fluoride, bifluoride, cyanide or azide ions or a suitable Lewis acid, Lewis base or selected oxyanion. Such polymerization processes have become known in the art as Group Transfer Polymerization (Webster et al., "Group Transfer Polymerization--A New and Versatile Kind of Addition Polymerization", J. Am. Chem. Soc. 105, 5706 (1983)). The disclosures of the aforesaid patents and patent applications on Group Transfer Polymerization are incorporated herein by reference for purpose of supporting the description of the present invention and are hereinafter referred to as "the foregoing patents and patent applications".